# Copyright (C) 2019 GNUnet e.V.
#
# This code is derived from code contributed to GNUnet e.V.
# by nikita <nikita@n0.is> and based on code by Florian Dold.
#
# Permission to use, copy, modify, and/or distribute this software for
# any purpose with or without fee is hereby granted.
#
# THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL
# WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED
# WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE
# AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL
# DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA
# OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER
# TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
# PERFORMANCE OF THIS SOFTWARE.
#
# SPDX-License-Identifier: 0BSD
import os
import sitegen.myshutil as shutil
import os.path
import sys
import re
import gettext
import glob
import codecs
import jinja2
from pathlib import Path, PurePosixPath, PurePath
from ruamel.yaml import YAML
from datetime import datetime
import html.parser
from bs4 import BeautifulSoup
import sitegen.i18nfix as i18nfix
from sitegen.timeutil import time_rfc822, time_now, conv_date_rfc822


PROPERTIES_YML = "properties.yml"

def html2text(html_str):
    class extractText(html.parser.HTMLParser):
        def __init__(self):
            super(extractText, self).__init__()
            self.result = []

        def handle_data(self, data):
            self.result.append(data)

        def text_in(self):
            return "".join(self.result)

    k = extractText()
    k.feed(html_str)
    return k.text_in()


def cut_text(filename, count):
    with open(filename) as html:
        soup = BeautifulSoup(html, features="lxml")
        for script in soup(["script", "style"]):
            script.extract()
        k = []
        for i in soup.findAll("p")[1]:
            k.append(i)
        b = "".join(str(e) for e in k)
        text = html2text(b.replace("\n", " "))
        textreduced = (text[:count] + " [...]") if len(text) > count else (text)
        return textreduced


def extract_body(text, content_id="newspost-content"):
    """Extract the body of some HTML and
    return it wrapped in an <article> tag."""
    soup = BeautifulSoup(text, features="lxml")
    content = soup.find(id=content_id)
    if content is None:
        raise Error("can't extract content")
    return content.prettify()


def make_helpers(root, in_file, locale):
    """Return a dictionary of helpers that should be available in
    the template."""

    def self_localized(other_locale, relative=False):
        """
        Return URL for the current page in another locale.
        """
        abs_file = Path(in_file).resolve()
        baseurl = os.environ.get("BASEURL")
        if relative or not baseurl:
            return (
                "../"
                + other_locale
                + "/"
                + str(in_file.relative_to(root / "template")).rstrip(".j2")
            )
        else:
            return (
                baseurl
                + other_locale
                + "/"
                + str(Path(abs_file).relative_to(root / "template")).rstrip(".j2")
            )

    def url(x, virtual=False):
        abs_file = Path(in_file).resolve()

        def check_exists():
            if virtual:
                return True
            if Path(root / "static" / x).exists():
                return True
            if Path(root / "template" / (x + ".j2")).exists():
                return True
            if Path(root / "template" / (x + ".j2")).exists():
                return True
            slashpos = x.find("/")
            if slashpos < 0:
                return False
            rest = x[slashpos+1:]
            # Heuristic search for translated file
            if Path(root / "template" / (rest + ".j2")).exists():
                return True
            return False

        if not check_exists():
            raise FileNotFoundError("can't find " + x)

        url = ""
        current_location = Path(abs_file).relative_to(root / "template")
        for p in current_location.parts:
            url += "../"
        return url + x

    def url_static(filename):
        return url(filename)

    def url_dist(filename):
        return url("dist/" + filename)

    def url_localized(filename):
        return url(locale + "/" + filename)

    def svg_localized(filename):
        lf = root / "static" / filename / "." / locale / ".svg"
        if locale == "en" or not lf.is_file():
            return url(filename + ".svg")
        else:
            return url(filename + "." + locale + ".svg")

    def get_abstract(name, length):
        return cut_text(root / "template" / (name + ".j2"), length)

    return dict(
        self_localized=self_localized,
        url_localized=url_localized,
        url_static=url_static,
        url_dist=url_dist,
        url=url,
        svg_localized=svg_localized,
        now=time_rfc822(time_now()),
        conv_date_rfc822=conv_date_rfc822,
        get_abstract=get_abstract,
    )


def copytree(src, dst, symlinks=False, ignore=None):
    for item in os.listdir(src):
        s = os.path.join(src, item)
        d = os.path.join(dst, item)
        if os.path.isdir(s):
            shutil.copytree(s, d, symlinks, ignore, dirs_exist_ok=True)
        else:
            shutil.copy2(s, d)


class SiteGenerator:
    def __init__(self, debug=0, root="."):
        self.root = Path(root).resolve()
        self.debug = debug
        loader = jinja2.ChoiceLoader(
            [
                jinja2.FileSystemLoader(str(self.root / "template")),
                jinja2.PrefixLoader(
                    {"common": jinja2.FileSystemLoader(str(self.root / "common"))}
                ),
            ]
        )
        env = jinja2.Environment(
            loader=loader,
            extensions=["jinja2.ext.i18n"],
            lstrip_blocks=True,
            trim_blocks=True,
            undefined=jinja2.StrictUndefined,
            autoescape=False,
        )
        env.filters["extract_body"] = extract_body
        env.newstyle_gettext = True
        self.env = env
        # NOTE : read-in properties.yml and afterwards all *.yml in properties.d
        properties = {}
        yaml = YAML(typ="safe")
        yaml.preserve_quotes = True
        properties.update(yaml.load(self.root/PROPERTIES_YML))
        properties_dir =  PROPERTIES_YML.removesuffix('.yml') + '.d'
        for filepath in Path(self.root/properties_dir).glob('*.yml'):
            properties.update(yaml.load(filepath))
        self.config = properties

        self.baseurl = os.environ.get("BASEURL")
        if not self.baseurl:
            self.baseurl = self.config["siteconf"].get("baseurl")

    def run_localized(self, locale, tr):
        conf = self.config
        root = self.root
        env = self.env
        template_dir = root / "template"
        for in_file in template_dir.glob("**/*.j2"):
            tmpl_filename = str(in_file.resolve().relative_to(template_dir))
            tmpl = env.get_template(tmpl_filename)

            filename = tmpl_filename.rstrip(".j2")

            content = tmpl.render(
                lang=locale,
                lang_full=conf["langs_full"][locale],
                conf=conf,
                siteconf=conf["siteconf"],
                meetingnotesdata=conf["meetingnotes"],
                newsdata=conf["newsposts"],
                newsposts=conf["newsposts"],
                videosdata=conf["videoslist"],
                filename=filename,
                **make_helpers(root, in_file, locale),
            )

            out_name = root / "rendered" / locale / str(tmpl_filename).rstrip(".j2")
            Path(out_name).parent.mkdir(parents=True, exist_ok=True)
            with codecs.open(out_name, "w", encoding="utf-8") as f:
                try:
                    f.write(content)
                except:
                    print(e)

    def emit_sitemap(self):
        p = self.root / "rendered"
        links = sorted(p.rglob("*.html"))
        t0 = datetime.now()
        timestamp = t0.strftime("%Y-%m-%d")

        o = p / "sitemap.xml"
        with o.open("w") as f:
            f.write('<?xml version="1.0" encoding="UTF-8"?>\n')
            f.write("<urlset\n")
            f.write('xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"\n')
            f.write('xsi:schemaLocation="http://www.sitemaps.org/schemas/sitemap/0.9 ')
            f.write('http://www.sitemaps.org/schemas/sitemap/0.9/sitemap.xsd"\n')
            f.write('xmlns="http://www.sitemaps.org/schemas/sitemap/0.9">\n')
            for link in links:
                href = self.baseurl + str(link.relative_to(p))
                f.write(
                    "<url><loc>"
                    + href
                    + "</loc><lastmod>"
                    + timestamp
                    + "</lastmod><priority>1.0</priority></url>\n"
                )
            f.write("</urlset>\n")

    def run(self):
        conf = self.config
        root = self.root

        for l in root.glob("locale/*/"):

            if not l.is_dir():
                # https://bugs.python.org/issue22276
                continue

            locale = str(PurePath(l).name)

            try:
                tr = gettext.translation(
                    "messages", localedir="locale", languages=[locale]
                )
            except FileNotFoundError as e:
                print(
                    f"WARNING: unable to find translations for locale '{locale}'",
                    file=sys.stderr,
                )
                continue

            tr.gettext = i18nfix.wrap_gettext(tr.gettext)
            env = self.env

            env.install_gettext_translations(tr, newstyle=True)

            if locale not in conf["langs_full"]:
                print(
                    f"WARNING: skipping '{locale}, as 'langs_full' is not configured'",
                    file=sys.stderr,
                )
                continue

            self.run_localized(locale, tr)

        Path(root / "rendered").mkdir(exist_ok=True)
        copytree(root / "static", root / "rendered")

        self.emit_sitemap()